Deployment mechanisms for surgical instruments

ABSTRACT

A deployment mechanism for selectively deploying and retracting an energizable member and/an insulative member relative to an end effector assembly of a surgical instrument includes one or more actuators, a clutch assembly, and a drive assembly. The clutch assembly is configured to couple to the actuator(s) to provide rotational motion in the first direction in response to such rotation of the actuator(s) and to decouple from the actuator(s) in response to rotation thereof in the second direction. The drive assembly is operably coupled to the clutch assembly and is configured to convert the rotational motion provided by the clutch assembly into longitudinal motion to translate the energizable member and/or insulative member from a storage position to a deployed position and to translate the energizable member and/or the insulative member from the deployed position back to the storage position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/668,096, filed on Aug. 3, 2017, which is acontinuation application of U.S. patent application Ser. No. 14/542,858,filed on Nov. 17, 2014, now U.S. Pat. No. 9,724,153, the entire contentsof each of which are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to surgical instruments and, moreparticularly, to deployment mechanisms for deploying, e.g., actuating,one or more components of a surgical instrument.

Background of Related Art

Many surgical instruments include one or more movable handles, levers,actuators, triggers, etc. for actuating and/or manipulating one or morefunctional components of the surgical instrument. For example, asurgical forceps may include a movable handle that is selectivelycompressible relative to a stationary handle for moving first and secondjaw members of the forceps between spaced-apart and approximatedpositions for grasping tissue therebetween. Such a forceps may furtherinclude a trigger for selectively deploying a knife between the jawmembers to cut tissue grasped therebetween.

As can be appreciated, as additional functional components are added tothe surgical instrument, additional deployment structures or deploymentstructures capable of actuating more than one component are required.However, multiple deployment structures and/or combined deploymentstructures may be limited by spatial constraints within the housing ofthe surgical instrument, functional constraints of the components (e.g.,where a combined deployment structure imparts additional forcerequirements for deploying one or more of the components coupledthereto), and/or may overly complicate the operable components of thesurgical instrument.

SUMMARY

As used herein, the term “distal” refers to the portion that is beingdescribed that is further from a user, while the term “proximal” refersto the portion that is being described that is closer to a user.Further, to the extent consistent, any of the aspects described hereinmay be used in conjunction with any of the other aspects describedherein.

Provided in accordance with aspects of the present disclosure is adeployment mechanism for selectively deploying and retracting anenergizable member and/or an insulative member relative to an endeffector assembly of a surgical instrument. The deployment assemblyincludes one or more actuators, a clutch assembly, and a drive assembly.The one or more actuators are rotatable in a first direction from anun-actuated position to an actuated position and are rotatable in asecond direction from the actuated position back to the un-actuatedposition. The clutch assembly is associated with the one or moreactuators and is configured to couple to the one or more actuators toprovide rotational motion in the first direction in response to rotationof the one or more actuators in the first direction. The clutch assemblyis further configured to decouple from the one or more actuators inresponse to rotation of the one or more actuators in the seconddirection. The drive assembly is operably coupled to the clutch assemblyand the energizable member and/or the insulative member. The driveassembly is configured to convert the rotational motion provided by theclutch assembly into longitudinal motion to translate the energizablemember and/or the insulative member from a storage position to adeployed position and from the deployed position back to the storageposition.

In an aspect of the present disclosure, the clutch assembly includes aclutch gear. In such aspects, the drive assembly includes one or moredrive gears operably coupled to the clutch gear for transferringrotational motion of the clutch gear to the at least one drive gear.Further, an intermediate gear may be operably disposed between theclutch gear and the one or more drive gears.

In another aspect of the present disclosure, the clutch assemblyincludes a first pulley wheel, the drive assembly includes at secondpulley wheel, and a pulley belt is operably coupled between the firstand second pulley wheels for transferring rotational motion of the firstpulley wheel to the second pulley wheel.

In still another aspect of the present disclosure, the drive assemblyfurther includes an arm operably coupled between the clutch assembly andthe energizable member and/or the insulative member. The arm iscontinuously rotatable in one direction such that rotation of the armthrough a first portion of a revolution translates the energizablemember and/or the insulative member from the storage position to thedeployed position, and such that rotation of the arm through a secondportion of the revolution translates the energizable member and/or theinsulative member from the deployed position back to the storageposition.

In yet another aspect of the present disclosure, the deploymentmechanism is configured to define a ratio of a degree of rotation of theactuator(s) relative to a degree of rotation of the arm of less than orequal to about 1:3.

In still yet another aspect of the present disclosure, the arm includesa hand disposed at a free end thereof and drive assembly furtherincludes an upright member and a slider. The upright member defines aslot that extends in generally perpendicular orientation relative to anaxis of translation of the energizable member and/or the insulativemember and the hand of the arm is engaged within the slot. The slider iscoupled to the upright member and the energizable member and/or theinsulative member. As a result of the above-noted configuration,rotation of the arm in response to the rotational motion provided by theclutch assembly moves the hand along the slot and urges the uprightmember to translate the slider to thereby translate the energizablemember and/or the insulative member from the storage position to thedeployed position and to translate the energizable member and/or theinsulative member from the deployed position back to the storageposition.

In another aspect of the present disclosure, the drive assembly furtherincludes a linkage bar having a first end pivotably coupled to a freeend of the arm and a second end, and a slider pivotably coupled to thesecond end of the linkage bar and coupled to the energizable memberand/or the insulative member. As a result of this configuration,rotation of the arm in response to the rotational motion provided by theclutch assembly moves the linkage to translate the slider to therebytranslate the energizable member and/or the insulative member from thestorage position to the deployed position and to translate theenergizable member and/or the insulative member from the deployedposition back to the storage position.

In yet another aspect of the present disclosure, the clutch assembly anddrive assembly are operably mounted on one or more support members.

In still another aspect of the present disclosure, the one or moresupport members include a guide configured to guide translation of theenergizable member and/or the insulative member between the storageposition and the deployed position.

In still yet another aspect of the present disclosure, the one or moresupport members include at least one locking member configured toreleasably lock the energizable member and/or the insulative member inone of the storage position or the deployed position.

Also provided in accordance with aspects of the present disclosure is asurgical instrument including a housing, a shaft extending distally fromthe housing, an end effector assembly disposed at a distal end of theshaft, a deployable assembly including an energizable member and/or aninsulative member that is selectively movable relative to the endeffector assembly between a storage condition and a deployed condition,and a deployment mechanism for selectively moving the deployableassembly between the storage condition and the deployed condition. Thedeployment mechanism may include any of the aspects and features of thedeployment mechanism detailed above, and/or any of the other aspects andfeatures detailed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described herein withreference to the drawings wherein like reference numerals identifysimilar or identical elements:

FIG. 1 is a front, perspective view of an endoscopic surgical forcepsconfigured for use in accordance with the present disclosure;

FIG. 2A is an enlarged, front, perspective view of an end effectorassembly of the forceps of FIG. 1, wherein jaw members of the endeffector assembly are disposed in a spaced-apart position and wherein amonopolar assembly is disposed in a storage condition;

FIG. 2B is an enlarged, front, perspective view of the end effectorassembly of FIG. 2A, wherein the jaw members are disposed in anapproximated position and wherein the monopolar assembly is disposed inthe storage condition;

FIG. 2C is an enlarged, front, perspective view of the end effectorassembly of FIG. 2B, wherein the jaw members are disposed in theapproximated position and wherein the monopolar assembly istransitioning from the storage condition to a deployed condition;

FIG. 2D is an enlarged, front, perspective view of the end effectorassembly of FIG. 2B, wherein the monopolar assembly is disposed in thedeployed condition;

FIG. 3 is a perspective view of the proximal end of the forceps of FIG.1 with a portion of the housing and internal components thereof removedto unobstructively illustrate a deployment mechanism provided inaccordance with the present disclosure;

FIG. 4 is an exploded, perspective view of the deployment mechanism ofFIG. 3;

FIG. 5 is an exploded, perspective view of a clutch assembly of thedeployment mechanism of FIG. 3;

FIG. 6 is a perspective view of the guide assembly of the deploymentmechanism of FIG. 3;

FIG. 7A is a perspective view of the deployment mechanism of FIG. 3 witha support portion removed and wherein the deployment mechanism isdisposed in an un-actuated condition;

FIG. 7B is a perspective view of the deployment mechanism of FIG. 3 withthe support portion removed and wherein the deployment mechanism isdisposed in an actuated condition;

FIG. 8A is a perspective view of the guide assembly of the deploymentmechanism of FIG. 3, wherein the guide member is approaching a proximallocking member;

FIG. 8B is a perspective view of the guide assembly of the deploymentmechanism of FIG. 3, wherein the guide member is approaching a distallocking member of the guide assembly;

FIG. 9A is a perspective view another deployment mechanism provided inaccordance with the present disclosure with a support member removed andwherein the deployment mechanism is disposed in an un-actuatedcondition;

FIG. 9B is a perspective view of the deployment mechanism of FIG. 9Awith the support member removed and wherein the deployment mechanism isdisposed in an actuated condition;

FIG. 10A is a perspective view another deployment mechanism provided inaccordance with the present disclosure with a support portion removedand wherein the deployment mechanism is disposed in an un-actuatedcondition;

FIG. 10B is a perspective view of the deployment mechanism of FIG. 10Awith the support portion removed and wherein the deployment mechanism isdisposed in an actuated condition;

FIG. 11 is an exploded, perspective view of a clutch assembly providedin accordance with the present disclosure and configured for use withany of the deployment mechanisms detailed herein; and

FIG. 12 is longitudinal, cross-sectional view of the clutch assembly ofFIG. 11.

DETAILED DESCRIPTION

Referring generally to FIG. 1, a forceps provided in accordance with thepresent disclosure is shown generally identified by reference numeral10. Forceps 10, as will be described below, is configured to operate inboth a bipolar mode, e.g., for grasping, treating, and/or dissectingtissue, and a monopolar mode, e.g., for treating and/or dissectingtissue. Although the present disclosure is shown and described withrespect to forceps 10, the aspects and features of the presentdisclosure are equally applicable for use with any suitable surgicalinstrument or portion(s) thereof for selectively actuating, moving,and/or deploying one or more assemblies and/or components of thesurgical instrument. Obviously, different connections and considerationsapply to each particular instrument and the assemblies and/or componentsthereof; however, the aspects and features of the present disclosureremain generally consistent regardless of the particular instrument,assemblies, and/or components provided.

Continuing with reference to FIG. 1, forceps 10 includes a housing 20, ahandle assembly 30, a trigger assembly 60, a rotating assembly 70, adeployment mechanism 80, an end effector assembly 100, and a monopolarassembly 200. Forceps 10 further includes a shaft 12 having a distal endconfigured to mechanically engage end effector assembly 100 and aproximal end that mechanically engages housing 20. Forceps 10 alsoincludes an electrosurgical cable 2 that connects forceps 10 to agenerator (not shown) or other suitable power source, although forceps10 may alternatively be configured as a battery powered instrument.Cable 2 includes wires (not shown) extending therethrough that havesufficient length to extend through shaft 12 in order to provideelectrical energy to at least one of the electrically-conductivesurfaces 112, 122 (FIG. 2A) of jaw members 110, 120, respectively, ofend effector assembly 100, e.g., upon activation of activation switch 4in a bipolar mode. One or more of the wires (not shown) of cable 2extends through housing 20 in order to provide electrical energy tomonopolar assembly 200, e.g., upon activation of activation switch 4 ina monopolar mode. Rotating assembly 70 is rotatable in either directionto rotate end effector assembly 100 and monopolar assembly 200 relativeto housing 20. Housing 20 houses the internal working components offorceps 10.

Referring to FIGS. 2A and 2B, end effector assembly 100 is attached atthe distal end of shaft 12 and includes opposing jaw members 110, 120pivotably coupled to one another. Each of the jaw members 110 and 120includes a jaw body 111, 121 supporting the respectiveelectrically-conductive surface 112, 122, and a respectiveproximally-extending jaw flange 114, 124. Flanges 114, 124 are pivotablycoupled to one another to permit movement of jaw members 110, 120relative to one another between a spaced-apart position (FIG. 2A) and anapproximated position (FIG. 2B) for grasping tissue between surfaces112, 122. One or both of surfaces 112, 122 are adapted to connect to asource of energy (not shown), e.g., via the wires (not shown) of cable 2(FIG. 1), and are configured to conduct energy through tissue graspedtherebetween to treat, e.g., seal, tissue. More specifically, in someembodiments, end effector assembly 100 defines a bipolar configurationwherein surface 112 is charged to a first electrical potential andsurface 122 is charged to a second, different electrical potential suchthat an electrical potential gradient is created for conducting energybetween surfaces 112, 122 and through tissue grasped therebetween fortreating e.g., sealing, tissue. Activation switch 4 (FIG. 1) is operablycoupled between the source of energy (not shown) and surfaces 112, 122,thus allowing the user to selectively apply energy to surfaces 112, 122of jaw members 110, 120, respectively, of end effector assembly 100during a bipolar mode of operation.

End effector assembly 100 is designed as a unilateral assembly, i.e.,where jaw member 120 is fixed relative to shaft 12 and jaw member 110 ismovable relative to shaft 12 and fixed jaw member 120. However, endeffector assembly 100 may alternatively be configured as a bilateralassembly, i.e., where both jaw member 110 and jaw member 120 are movablerelative to one another and to shaft 12. In some embodiments, a knifechannel 125 may be defined within one or both of jaw members 110, 120 topermit reciprocation of a knife 64 (FIG. 2B) therethrough, e.g., uponactuation of a trigger 62 of trigger assembly 60, to cut tissue graspedbetween jaw members 110, 120.

Referring to FIGS. 1-2D, monopolar assembly 200 includes an insulativesleeve 210, an energizable rod member 220, and a proximal hub 230 (FIG.3). Insulative sleeve 210 is slidably disposed about shaft 12 and isselectively movable about and relative to shaft 12 and end effectorassembly 100 between a storage position (FIGS. 2A and 2B), whereininsulative sleeve 210 is disposed proximally of end effector assembly100, and a deployed position (FIG. 2D), wherein insulative sleeve 210 issubstantially disposed about end effector 100 so as to electricallyinsulate surfaces 112, 122 of jaw members 110, 120, respectively. Withmomentary reference to FIG. 3, proximal hub 230 is engaged to insulativesleeve 210 at the proximal end of insulative sleeve 210 and also engagesthe proximal end of energizable rod member 220. Further, proximal hub230 is coupled to deployment mechanism 80 (FIGS. 1 and 3) such that, asdetailed below, deployment mechanism 80 is selectively actuatable totranslate proximal hub 230 along a translation axis through housing 20and relative to shaft 12 to thereby move monopolar assembly 200 betweenits storage and deployed conditions (FIGS. 2B and 2D, respectively). Thetranslation axis may be parallel with an axis defined by shaft 12, maybe coaxial with the axis of shaft 12, or may be non-parallel relativethereto.

Referring again to FIGS. 1-2D, energizable rod member 220 extends fromproximal hub 230 (FIG. 6), through sleeve 210, and distally therefrom,ultimately defining an electrically-conductive distal tip 224.Energizable rod member 220 and, more specifically, distal tip 224thereof, functions as the active electrode of monopolar assembly 200.The one or more wires (not shown) extending from cable 2 through housing20 (see FIG. 1), are coupled to energizable rod member 220 to provideenergy to energizable rod member 220, e.g., upon actuation of activationswitch 4 (FIG. 1) in a monopolar mode, for treating tissue in amonopolar mode of operation. Energizable rod member 220 is movablebetween the storage position (FIG. 2B) and the deployed position (FIG.2D). In the storage position (FIG. 2B), distal tip 224 of rod member 220is disposed within an insulated groove 126 defined within flange 124 ofjaw member 120, although other configurations are also contemplated,e.g., distal tip 224 of rod member 220 may simply be positionedalongside flange 124 in the storage condition. Insulated groove 126electrically-insulates distal tip 224 of rod member 220 fromelectrically-conductive surfaces 112, 122 of jaw members 110, 120,respectively, and from surrounding tissue when disposed in the storageposition. Alternatively, distal tip 224 of rod member 220 may only beinsulated from surface 112. In such configurations, distal tip 224 ofrod member 220 is capable of being energized to the same polarity assurface 122.

In the deployed position (FIG. 2D), distal tip 224 of rod member 220 ofmonopolar assembly 200 extends distally from end effector assembly 100and insulative sleeve 210, which substantially surrounds end effectorassembly 100. In this position, energy may be applied to distal tip 224of rod member 220 to treat tissue, e.g., via activation of activationswitch 4 (FIG. 1) in the monopolar mode. Distal tip 224 may behook-shaped (as shown), or may define any other suitable configuration,e.g., linear, ball, circular, angled, etc.

Insulative sleeve 210 and rod member 220 of monopolar assembly 200 arecoupled to one another via proximal hub 230 (FIG. 3), as will bedescribed in greater detail below, such that insulative sleeve 210 androd member 220 move in concert, e.g., together, with one another betweentheir storage positions (FIGS. 2A and 2B), collectively the storagecondition of monopolar assembly 200, and their deployed positions (FIG.2D), collectively the deployed condition of monopolar assembly 200, uponselective translation of proximal hub 230 through housing 20 andrelative to shaft 12 (see FIG. 1).

With reference again to FIG. 1, handle assembly 30 includes a movablehandle 40 and a fixed handle 50. Fixed handle 50 is integrallyassociated with housing 20 and movable handle 40 is movable relative tofixed handle 50. Movable handle 40 is movable relative to fixed handle50 between an initial position, wherein movable handle 40 is spaced fromfixed handle 50, and a compressed position, wherein movable handle 40 iscompressed towards fixed handle 50. A biasing member (not shown) may beprovided to bias movable handle 40 towards the initial position. Movablehandle 40 is ultimately connected to a drive assembly (not shown)disposed within housing 20 that, together, mechanically cooperate toimpart movement of jaw members 110, 120 between the spaced-apartposition (FIG. 2A), corresponding to the initial position of movablehandle 40, and the approximated position (FIG. 2B), corresponding to thecompressed position of movable handle 40. Any suitable drive assemblyfor this purpose may be provided such as, for example, the driveassembly disclosed in U.S. patent application Ser. No. 14/052,871, filedon Oct. 14, 2013, the entire contents of which are incorporated hereinby reference.

Trigger assembly 60 includes trigger 62 that is operably coupled toknife 64 (FIG. 2B). Trigger 62 of trigger assembly 60 is selectivelyactuatable to advance knife 64 (FIG. 2B) from a retracted position,wherein knife 64 (FIG. 2B) is disposed proximally of jaw members 110,120, to an extended position, wherein knife 64 (FIG. 2B) extends atleast partially between jaw members 110, 120 and through knifechannel(s) 125 (FIG. 2A) to cut tissue grasped between jaw members 110,120.

Detailed below with respect to FIGS. 3-12, in conjunction with FIGS.1-2D, are various embodiments of deployment mechanisms for selectivelydeploying monopolar assembly 200 (or similar monopolar assemblies). Tothe extent consistent, the various deployment mechanisms detailedhereinbelow, although described separately, may include any or all ofthe features of any or all of the other deployment mechanisms detailedhereinbelow, and may be utilized with forceps 10 or any other suitablesurgical instrument.

Referring to FIGS. 3-7B, deployment mechanism 80 is configured forselectively translating proximal hub 230 relative to housing 20 andshaft 12 (FIG. 1) to thereby transition monopolar assembly 200 betweenits storage condition (FIGS. 2A and 2B) and its deployed condition (FIG.2D). Deployment mechanism 80 generally includes a pair of actuators 82,first and second support members 150, 160 (second support member 160 hasbeen removed from FIGS. 3, 7A, and 7B to better illustrate thecomponents of deployment assembly 80), respectively, a clutch assembly170, and a gear drive assembly 180. Each of these components will bedetailed, in turn, below.

Actuators 82 are rotatably mounted on either side of housing 20 (FIG. 1)and are positioned to readily enable distal actuation thereof, e.g.,clockwise rotation of either or both actuators 82 from the orientationshown in FIG. 1, to transition monopolar assembly 200 (FIGS. 2A-2D)between the storage condition (FIG. 2B) and the deployed condition (FIG.2D). Actuators 82 are engaged about opposite ends of a pin 84 thatextends between actuators 82 and through housing 20, support members150, 160, and clutch assembly 170. More specifically, pin 84 is engagedwith actuator plate 176 of clutch assembly 170 such that rotation ofeither or both actuators 82 effects corresponding rotation of pin 84and, thus, actuator plate 176 of clutch assembly 170. A torsion spring85 is disposed about pin 84 and configured to rotationally bias pin 84,e.g., in a counter-clockwise direction from the orientation shown inFIG. 1, thereby biasing actuators 82 towards their un-actuated positionsshown in FIG. 1.

Referring to FIG. 4, first and second support members 150, 160,respectively, are configured to support the various components ofdeployment mechanism 80 therebetween, retain the various components ofdeployment mechanism 80 in operable engagement with one another, andsecure deployment mechanism 80 within housing 20. First support member150 defines a plate-like configuration and includes a plurality ofmounting aperture 152 defined therethrough. Second support member 160likewise defines a plurality of mounting apertures 162 configured toalign with mounting apertures 152 of first support member 150. Each pairof aligned mounting apertures 152, 162 is configured to receive asecurement member 153 (FIG. 3), e.g., screw, pin, etc., for securingfirst and second support members 150, 160 to one another and/or to theinterior of housing 20 (FIG. 3). First and second support members 150,160 each further include a pin aperture 154, 164 that rotatably receivespin 84.

First support member 150 additionally includes first and second geardrive apertures 155, 156 defined therethrough for rotatably mountingfirst drive gear 182 and second drive gear 184 of gear drive assembly180 to first support member 150. An intermediate gear 158 is rotatablymounted on first support member 150 and is positioned between pinaperture 154 and gear drive apertures 155, 156 such that, upon assembly,intermediate gear 158 operably couples clutch mechanism 170 and geardrive assembly 180 to one another for transmitting rotational motiontherebetween, as detailed below.

Second support member 160 includes a cylindrical housing member 166through which pin 84 extends and that is configured to rotatably receiveactuator plate 176 of clutch mechanism 170. Second support member 160further includes a guide body 167 defining a guide track 168 and a guideslot 169. As detailed below, guide body 167 is configured to guidetranslation of slider 189 of gear drive assembly 180 (see FIG. 6) and,thus, to guide the transition of monopolar assembly 200 between thestorage condition (FIG. 2B) and the deployed condition (FIG. 2D).

Referring to FIGS. 3-5, clutch assembly 170 generally includes a basemember 172, a clutch plate 174, a biasing member 175, an actuator plate176, and an actuator gear 178. Actuator plate 176, as noted above, issecured about pin 84 and is rotatably received within cylindricalhousing member 166 of second support member 160 such that, upon rotationof either or both actuators 82 to thereby rotate pin 84, actuator plate176 is rotated within and relative to cylindrical housing member 166.

Base member 172 of clutch assembly 170 defines a generally cylindricalconfiguration having an annular wall 172 a and an end wall 172 b thatcooperate to define a cavity 172 c. End wall 172 b defines a centralaperture 172 d configured to receive pin 84 therethrough for rotatablymounting base member 172 about pin 84. Actuator gear 178 is likewiserotatably disposed about pin 84 and is fixed to the outer surface of endwall 172 b of base member 172 (or otherwise secured thereto) such thatrotation of base member 172 effects corresponding rotation of actuatorgear 178. Actuator gear 178 is disposed in meshed engagement withintermediate gear 158 such that rotation of actuator gear 178 effectsopposite rotation of intermediate gear 158.

The open end of annular wall 172 a of base member 172, e.g., the end ofannular wall 172 a opposite end wall 172 b, defines a plurality ofspaced-apart notches 172 e arranged annularly thereabout. Clutch plate174 includes a plurality of spaced-apart, radial protrusions 174 aextending outwardly from the annular outer periphery therefrom and isshaped complementary to the open end of annular wall 172 a of basemember 172. Such a configuration allows each of the protrusions 174 a tobe received within one of the notches 172 e defined within base member172, thereby inhibiting relative rotation between clutch plate 174 andbase member 172. Biasing member 175 is disposed within cavity 172 c ofbase member 172 between end wall 172 b and clutch plate 174 so as tobias clutch plate 174 apart from end wall 172 b and into abutment withactuator plate 176, which is maintained adjacent clutch plate 174 viacylindrical housing member 166 of second support member 160.

Respective opposed surfaces 176 a, 174 b of actuator plate 176 andclutch plate 174, respectively, are maintained in abutment with oneanother under the bias of biasing member 175. Actuator plate 176 andclutch plate 174 each further include a plurality of one-way tabs 176 b,174 c, respectively, disposed on the opposed surfaces 176 a, 174 bthereof that are arranged to define a circumferential pattern. Tabs 176b, 174 c each include a surface 176 c, 174 d that extendsperpendicularly from the respective opposed surface 176 a, 174 b and acurved surface 176 d, 174 e that gradually extends from the respectiveopposed surface 176 a, 174 b in a curved manner. Thus, relative rotationbetween actuator plate 176 and clutch plate 174 is only permitted in onedirection, e.g., wherein curved surfaces 176 d, 174 e slide past oneanother (and clutch plate 176 is urged towards base member 172 againstthe bias of biasing member 175), and is inhibited in the second,opposite direction, e.g., wherein the perpendicular surfaces 176 c, 174d abut one another. As a result of the above-detailed configurations ofactuator plate 176 and clutch plate 174, rotation of either or both ofactuators 82 in the actuating direction, e.g., clockwise from theorientation shown in FIG. 1, urges the perpendicular surfaces 176 c oftabs 176 b of actuator plate 176 into abutment with perpendicularsurfaces 174 d of tabs 174 c of clutch plate 174 such that actuatorplate 176 and clutch plate 174 and, thus, base member 172 and actuatorgear 178, are rotated together with one another. On the other hand,return or release (under the bias of torsion spring 85) of either orboth of actuators 82, e.g., counter-clockwise from the orientation shownin FIG. 1, permits curved surfaces 176 d of tabs 176 b of actuator plate176 to slide over curved surfaces 174 e of tabs 174 c of clutch plate174 such that actuator plate 176, pin 84, and actuators 82 are rotatedrelative to clutch plate 174, base member 172, and actuator gear 178back to their respective initial positions without effecting rotation ofclutch plate 174, base member 172, or actuator gear 178. Thus, clutchassembly 170 functions as a one-way drive mechanism wherein actuatorgear 178 is rotatable in a single direction while actuators 82 arerepeatedly actuatable and releasable to drive such rotation of actuatorgear 178.

Referring still to FIGS. 3-5, gear drive assembly 180 includes a firstdrive gear 182 that is rotatably mounted on first support member 150,e.g., via a pin extending through first drive gear 182 and aperture 155,and is disposed in meshed engagement with intermediate gear 158 suchthat rotation of intermediate gear 158 effects rotation of first drivegear 182 in the opposite direction. First drive gear 182, in turn, isdisposed in meshed engagement with a second drive gear 184 that isrotatably mounted on first support member 150, e.g., via a pin extendingthrough second drive gear 184 and aperture 156.

An arm 185 is pinned to second drive gear 184 at a first end thereofsuch that rotation of second drive gear 184 effects correspondingrotation of arm 185. Arm 185 includes a hand 186 disposed at the second,opposite end of arm 185. Hand 186 is slidably received within a verticalslot 187 defined within an upright member 188 and is confined (relativeto upright member 188) to vertical motion within vertical slot 187. Aslider 189 is engaged to and extends distally from upright member 188.As a result of the above-configuration, as arm 185 is rotated through afirst half of its full circumferential rotation, e.g., wherein arm 185is moved in a generally distal direction, hand 186 is slid verticallythrough vertical slot 187 and pushes upright member 188 and, thus,slider 189 distally. On the other hand, as arm 185 is rotated throughthe second half of its full circumferential rotation, e.g., wherein arm185 is moved in a generally proximal direction, hand 186 is slidvertically through vertical slot 187 to pull upright member 188 and,thus, slider 189, proximally.

With additional reference to FIGS. 6, 7A, and 7B, slider 189 defines atransverse, cross-sectional configuration that is complementary to thatof guide track 168 of guide body 167 of second support member 160 and isengaged therein such that slider 189 is confined to longitudinallytranslation through guide body 167. Slider 189 is engaged to or formedwith proximal hub 230 of monopolar assembly 200 such that, as will bedescribed in greater detail below, translation of slider 189 throughguide body 167 urges monopolar assembly 200 through housing 20 andrelative to shaft 12 (FIG. 1) between the storage condition (FIGS. 2Aand 2B) and the deployed condition (FIG. 2D). More specifically, assecond drive gear 184 rotates arm 185 through its first half of rotationwherein arm is moved in a generally distal direction, hand 185 urgesupright member 188 and, thus, slider 189 distally, e.g., from theposition shown in FIG. 7A to the position shown in FIG. 7B, to urgemonopolar assembly 200 from the storage condition (FIGS. 2A and 2B)towards the deployed condition (FIG. 2D). On the other hand, as seconddrive gear 184 further rotates arm 185 through its second half ofrotation (to complete a full rotation thereof) wherein arm is moved in agenerally proximal direction, hand 185 urges upright member 188 and,thus, slider 189 proximally, e.g., from the position shown in FIG. 7Bback to the position shown in FIG. 7A, to urge monopolar assembly 200from the deployed condition (FIG. 2D) back towards the storage condition(FIGS. 2A and 2B).

Actuator gear 178, intermediate gear 158, first drive gear 182, andsecond drive gear 184 are configured to establish an advantageous gearratio therebetween such that minimal actuation of actuators 82 isrequired to fully deploy and retract monopolar assembly 200.Specifically, it has been found that a gear ratio of less than or equalto about 1:3, e.g., wherein at most a 60 degree rotation of either orboth actuators 82 effects a one-half rotation (180 degrees) of arm 185,which is sufficient to fully deploy or fully retract monopolar assembly200. With momentary reference to FIG. 1, such a configuration, takinginto account the ergonomic considerations of the movable handle 40,trigger 62, and actuators 82, enables a user to readily and effectivelymanipulate and utilize forceps 10 (FIG. 1) with a single hand, e.g.,wherein the user's index finger is positioned to actuate trigger 62, thethumb is positioned to actuate one of the actuators 82 (in both rightand left-handed use), and the remaining fingers are utilized to actuatemovable handle 40. The push to deploy and push to retract (e.g.,push-push) configuration of deployment mechanism 80 also facilitatesthis single-handed use in that retraction does not require an oppositemotion and, thus, the user's thumb can be readily utilized for bothdeployment and retraction. Other ratios and configurations, includingthose where two-handed use is required or advantageous, are alsocontemplated.

Referring additionally to FIGS. 8A and 8B, slider 189 may furtherinclude a locking pin 190 extending transversely therefrom and guidebody 167 may further include proximal and/or distal locking members 192,194 for releasably locking deployment mechanism 80 in the actuatedand/or un-actuated conditions, thereby releasably locking monopolarassembly 200 in the deployed and/or storage conditions. Locking pin 190,more specifically, extends transversely from slider 189 through guideslot 169 of guide body 167. Locking members 192, 194 are pivotablycoupled to guide body 167 at a first end thereof and define lockingtracks 196, 198, respectively, at the second, opposite ends thereof.Biasing members (not shown) may be provided to bias locking members 192,194 towards an initial position. Upon translation of slider 189 to theproximal or distal position corresponding to the storage or deployedcondition, respectively, of monopolar assembly 200, locking pin 190enters the respective locking track 196, 198 and urges the respectivelocking member 192, 194 to pivot against its bias. Locking tracks 196,198 include “catches” defined therein that are configured to releasablyretain locking pin 190 once the proximal or distal position,respectively, has been achieved, thereby releasably locking monopolarassembly 200 in the deployed or storage condition. Release of lockingpin 190 from locking tracks 196, 198 is effected by further translationof slider 189, e.g., distally from the distal position or proximallyfrom the proximal position, thereby permitting locking pin 190 to exitthe respective locking track 196, 198 and translate back in the oppositedirection, while the locking member 192, 194 is returned under bias toits initial position. Thus, the “distal” and “proximal” positions ofslider 189 are not the respective distal-most and proximal-mostpositions thereof, as a small amount of travel beyond these positions isprovided to enable unlocking of locking pin 190.

Referring to FIGS. 1-8B, the use and operation of forceps 10 in both thebipolar mode, e.g., for grasping, treating (for example, sealing),and/or cutting tissue, and the monopolar mode, e.g., forelectrical/electromechanical tissue treatment, is described. Turning toFIGS. 1 and 2A-2B, with respect to use in the bipolar mode, monopolarassembly 200 is maintained in the storage condition, wherein insulativesleeve 210 is positioned proximally of jaw members 110, 120, and distaltip 224 of energizable rod member 220 is disposed within insulativegroove 126 of jaw flange 124 of jaw member 120. At this point, movablehandle 40 is disposed in its initial position such that jaw members 110,120 are disposed in the spaced-apart position (FIG. 2A). Further,trigger 62 of trigger assembly 60 remains un-actuated such that knife 64(FIG. 2B) remains disposed in its retracted position.

Continuing with reference to FIGS. 1 and 2A-2B, with jaw members 110,120 disposed in the spaced-apart position (FIG. 2A), end effectorassembly 100 may be maneuvered into position such that tissue to begrasped, treated, e.g., sealed, and/or cut, is disposed between jawmembers 110, 120. Next, movable handle 40 is depressed, or pulledproximally relative to fixed handle 50 such that jaw member 110 ispivoted relative to jaw member 120 from the spaced-apart position to theapproximated position to grasp tissue therebetween (FIG. 2B). In thisapproximated position, energy may be supplied, e.g., via activation ofswitch 4, to surface 112 of jaw member 110 and/or surface 122 of jawmember 120 and conducted through tissue to treat tissue, e.g., to effecta tissue seal or otherwise treat tissue in the bipolar mode ofoperation. Once tissue treatment is complete (or to cut untreatedtissue), knife 64 (FIG. 2B) may be deployed from within shaft 12 tobetween jaw members 110, 120, e.g., via actuation of trigger 62 oftrigger assembly 60, to cut tissue grasped between jaw members 110, 120.

When tissue cutting is complete, trigger 62 may be released to returnknife 64 (FIG. 2B) to the retracted position. Thereafter, movable handle40 may be released or returned to its initial position such that jawmembers 110, 120 are moved back to the spaced-apart position (FIG. 2A)to release the treated and/or divided tissue.

For operation of forceps 10 in the monopolar mode, jaw members 110, 120are first moved to the approximated position, e.g., by depressingmovable handle 40 relative to fixed handle 50. A lockout mechanism forinhibiting deployment of monopolar assembly 200 prior to movement of jawmembers 110, 120 to the approximated positions may also be provided,such as the lockout mechanism described in U.S. patent application Ser.No. 14/276,465, filed on May 13, 2014, the entire contents of which areincorporated herein by reference. Once the approximated position hasbeen achieved, monopolar assembly 200 may be deployed by transitioningdeployment mechanism 80 from the un-actuated condition to the actuatedcondition. More specifically, in order to deploy monopolar assembly 200,either or both actuators 82 are rotated distally, e.g., clockwise fromthe orientation shown in FIG. 1, from the un-actuated position to theactuated position.

Rotation of either or both actuators 82, as detailed above, effectsrotation of pin 84 and actuator plate 176, which engages clutch plate174 and urges clutch plate 174, base member 172, and actuator gear 178to rotate similarly as actuators 82. Being in meshed engagement,rotation of actuator gear 178 effects opposite rotation of intermediategear 158 which, in turn, effects opposite rotation (relative tointermediate gear 158) of first drive gear 182. Rotation of first drivegear 182 effects opposite rotation of second drive gear 184 (relative tofirst drive gear 182) to thereby rotate arm 185 through its first halfof rotation, e.g., distally from the position shown in FIG. 7A to theposition shown in FIG. 7B. Such rotation of arm 185 slides hand 186vertically through vertical slot 187 of upright member 188 and urgesupright member 188 distally. Distal urging of upright member 188 urgesslider 189 distally through guide track 168 of guide body 167, therebytranslating proximal hub 230 of monopolar assembly 200 and, thus,insulative sleeve 210 and energizable rod member 220, distally relativeto housing 20, shaft 12, and end effector assembly 100 from theirstorage positions (the storage condition of monopolar assembly 200)(FIG. 2B), to their deployed positions (the deployed condition ofmonopolar assembly 200) (FIG. 2D).

Upon full actuation of either or both actuators 82 to deploy monopolarassembly 200, the actuator(s) 82 can be released, allowing actuatorplate 176 to rotate relative to clutch plate 174 (which remainsrelatively stationary) to thereby return the actuator(s) 82 to theirinitial position while monopolar assembly 200 remains disposed in thedeployed condition via engagement of locking pin 190 within lockingmember 194 and drive gear assembly 180 remains disposed in the actuatedcondition shown in FIG. 7B.

With monopolar assembly 200 locked in the deployed condition, activationswitch 4 may be actuated to supply energy to energizable rod member 220to treat, e.g., dissect or otherwise treat, tissue. During applicationof energy to tissue via energizable rod member 220, forceps 10 may bemoved relative to tissue, e.g., longitudinally, transversely, and/orradially, to facilitate electromechanical treatment of tissue.

At the completion of tissue treatment, either or both of actuators 82may be actuated a subsequent time, e.g., either or both actuators 82 mayonce again be rotated distally from the un-actuated position to theactuated position. This subsequent, or re-actuation of either or bothactuators 82, as detailed above, effects rotation of pin 84 and actuatorplate 176, which engages clutch plate 174 and thereby urges clutch plate174, base member 172, and actuator gear 178 to rotate. This rotation, inturn, rotates intermediate gear 158, first drive gear 182, and seconddrive gear 184 to thereby rotate arm 185 through the second halfrotation, e.g., proximally from the position shown in FIG. 7B back tothe position shown in FIG. 7A. Such rotation of arm 185 initially urgesslider 189 distally to disengage locking pin 190 from locking member194, thereby unlocking monopolar assembly 200 from the deployedcondition, and slides hand 185 vertically through vertical slot 187 ofupright member 188 while pulling upright member 188 proximally. Proximalpulling of upright member 188 pulls slider 189 proximally through guidetrack 168 of guide body 167, thereby translating proximal hub 230 ofmonopolar assembly 200 and, thus, insulative sleeve 210 and energizablerod member 220, proximally relative to housing 20, shaft 12, and endeffector assembly 100 from their deployed positions (the deployedcondition of monopolar assembly 200) (FIG. 2D) back to their storagepositions (the storage condition of monopolar assembly 200) (FIG. 2B).

Upon return of slider 189 to the proximal position, locking pin 190enters locking track 192 and is releasably engaged therein, therebylocking monopolar assembly 200 in the storage condition. Further, uponfull re-actuation of either or both actuators 82 to deploy monopolarassembly 200, the actuator(s) 82 can be released, allowing actuatorplate 178 to rotate relative to clutch plate 176 to thereby return theactuator(s) 82 to their initial position while monopolar assembly 200remains disposed in the storage condition via engagement of locking pin190 within locking member 192.

Turning now to FIGS. 9A and 9B, another embodiment of a deploymentmechanism provided in accordance with the present disclosure is showngenerally as deployment mechanism 380. Deployment mechanism 380 issimilar to and may include any or all of the features of deploymentmechanism 80 (FIGS. 3-8B). Accordingly, for purposes of brevity, onlythe differences between deployment mechanism 380 and deploymentmechanism 80 (FIGS. 3-8B) will be described in detail below.

Rather than providing a hand and upright member coupled to the secondend of the arm, as detailed above with respect to deployment mechanism80 (FIGS. 3-8B), deployment mechanism 380 includes a linkage bar 386pivotably coupled to the second end of arm 385 at its first end and toslider 389 at its second end. In use, as arm 385 is rotated through itsfirst half of rotation, e.g., in a generally distal direction, linkagebar 386 is pushed distally to thereby deploy monopolar assembly 200(FIGS. 2A-2D). On the other hand, as arm 385 is rotated through itssecond half of rotation, e.g., in a generally proximal direction,linkage bar 386 is pulled proximally to thereby retract monopolarassembly 200 (FIGS. 2A-2D). The use and operation of deploymentmechanism 380 is otherwise similar to that of deployment mechanism 80(FIGS. 3-8B), detailed above.

Turning now to FIGS. 10A and 10B, another embodiment of a deploymentmechanism provided in accordance with the present disclosure is showngenerally as deployment mechanism 480. Deployment mechanism 480 issimilar to and may include any or all of the features of deploymentmechanisms 80 (FIGS. 3-8B). Accordingly, for purposes of brevity, onlythe differences between deployment mechanism 480 and deploymentmechanism 80 (FIGS. 3-8B) will be described in detail below.

Deployment mechanism 480, rather than providing a hand and uprightmember coupled to the second end of the arm, as detailed above withrespect to deployment mechanism 80 (FIGS. 3-8B), includes a linkage bar486 coupled to arm 485, similarly as detailed above with respect todeployment mechanism 380 (FIGS. 9A and 9B). However, it is alsocontemplated that deployment mechanism 480 be configured similar todeployment mechanism 80 (FIGS. 3-8B) in this manner, e.g., thatdeployment mechanism 480 include a hand and upright member coupledbetween the arm and slider.

Further, rather than providing a plurality of gear members forconverting rotation of the actuators into longitudinal translation ofthe slider and, thus, deployment and retraction of monopolar assembly200 (FIGS. 2A-2D), deployment mechanism 480 includes a pulley system490. Pulley system 490 includes a first pulley wheel 492 coupled toclutch assembly 484 (similar to clutch assembly 170 of deploymentmechanism 80 (FIGS. 3-8B)) and a second pulley wheel 494 having thefirst end of arm 485 coupled thereto. A pulley belt 496 is disposedabout first and second pulley wheels 492, 494 are configured such thatrotation of first pulley wheel 492, imparted thereto via clutch assembly484, urges pulley belt 496 to rotate second pulley wheel 494. First andsecond pulley wheels 492, 494 and pulley belt 496 may be configured toestablish an advantageous pulley ratio therebetween such that minimalactuation of actuators 482 is required to fully deploy and retractmonopolar assembly 200 (FIGS. 2A-2D), similarly as detailed above withrespect to deployment mechanism 80 (FIGS. 3-8B).

First pulley wheel 492 of pulley system 490, as mentioned above, iscoupled to clutch assembly 484 of deployment mechanism 480 similarly aswith actuator gear 178 of clutch assembly 170 of deployment mechanism 80(see FIGS. 4 and 5). That is, first pulley wheel 492 is engaged with theclutch plate (not shown, similar to clutch plate 174 of deploymentmechanism 80 (FIG. 4)) of the clutch assembly 484 such that rotation ofactuator(s) 482 in a first direction effects rotation of first pulleywheel 492 and such that return of actuators 482 in the second, oppositedirection is effected without moving first pulley wheel 492. Secondpulley wheel 494 is coupled to arm 485 which is coupled to linkage bar486 which, in turn, is coupled to slider 489 such that, similarly asdetailed above, rotation of second pulley wheel 494 through a first halfof rotation, e.g., generally distally, deploys monopolar assembly 200(FIGS. 2A-2D) and such that further rotation of second pulley wheel 494through a second half of rotation, e.g., generally proximally, retractsmonopolar assembly 200 (FIGS. 2A-2D). The use and operation ofdeployment mechanism 480 is otherwise similar to that detailed abovewith respect to deployment mechanism 80 (FIGS. 3-8B).

Referring to FIGS. 11 and 12, another embodiment of a clutch assembly570 provided in accordance with the present disclosure is shownconfigured for use with deployment mechanism 480 (FIGS. 10A and 10B),although clutch assembly 570 may similarly be used with deploymentmechanism 80 (FIGS. 3-8B) and/or deployment mechanism 380 (FIGS. 9A and9B).

Clutch assembly 570 includes a first pulley wheel 572 that is similar tofirst pulley wheel 492 of deployment mechanism 480 (FIGS. 10A and 10B)except as detailed hereinbelow. However, in embodiments where clutchassembly 570 is utilized in deployment mechanism 80 (FIGS. 3-8B) and/ordeployment mechanism 380 (FIGS. 9A and 9B), first pulley wheel 572 isinstead an actuator gear similarly as detailed above with respect tothose deployment mechanism. First pulley wheel 572 of clutch assembly570 includes a body portion 573 defining an aperture 574 therethrough. Atubular extension 575 a extends transversely from body portion 573 andis disposed about aperture 574 to define a lumen that is an extension ofaperture 574. A plurality of radially-arranged, one-way teeth 575 b aredisposed about tubular extension 575 a adjacent body portion 573.

Clutch assembly 570 further includes an actuator hub 576, and first andsecond biasing members 578, 579, respectively. Actuator hub 576 definesan inner member 577 a that is configured to abut tubular extension 575 aof first pulley wheel 572 and includes an aperture 577 b extendingtherethrough. Aperture 577 b is configured to receive a pin 584 (similarto pin 84 (FIG. 3)) to engage actuator hub 576 with the actuator (notshown, similar to actuators 82 (FIG. 3). Pin 584 extends through and isrotatably disposed within aperture 574 of first pulley wheel 572 suchthat actuator hub 576 and pin 584 are together rotatable relative tofirst pulley wheel 572. Actuator hub 576 further includes an outerannular member 577 c spaced-apart from inner member 577 a to define aring-shaped recess 577 d therebetween.

As detailed below, first biasing member 578 is provided to return theactuator to the initial position after actuation, while second biasingmember 579, in conjunction with one-way teeth 575 b, provide the clutchfunctionality of clutch assembly 570 that enables actuation of theactuator to drive first pulley wheel 572, while first pulley wheel 572is retained in position upon return of the actuator to is initialposition. First biasing member 578 includes a first end 578 a thatextends into recess 577 d and is engaged within a slot 577 e definedwithin outer annular member 577 c. Likewise, second biasing member 579includes a first end 579 a that extends into recess 577 d and is engagedwithin a slot 577 f defined within inner member 577 a. Thus, first ends578 a, 579 a of first and second biasing members 578, 579, respectively,are rotationally fixed relative to actuator hub 576. First and secondbiasing members 578, 579 are configured as coiled torsion springswherein first biasing member 578 defines a larger diameter than secondbiasing member 579 so as to enable first biasing member 578 to bepositioned about second biasing member 579 (see FIG. 12).

Second end 578 b of first biasing member 578 is fixed (e.g., secured toone of the support members of the deployment mechanism and/or thehousing of the forceps) such that rotation of actuator hub 576 inresponse to actuation of one or both of the actuators torques firstbiasing member 578. Upon release of the actuator(s), the energy built upin first biasing member 578 is released, thereby urging the actuator(s)and actuator hub 576 back to their respective initial positions.

Second end 579 b of second biasing member 579 is operably positionedrelative to one-way teeth 575 b of first pulley wheel 572 such thatrotation of actuator hub 576 in a first direct, e.g., in response toactuation of one or both of the actuators, applies torque to secondbiasing member 579 and urges second end 579 b of second biasing member579 to rotate into contact with the perpendicular surface of one of theone-way teeth 575 b of first pulley wheel 572 to likewise urge firstpulley wheel 572 to rotate. Similarly as noted above with respect todeployment mechanism 480 (FIGS. 10A and 10B), rotation of first pulleywheel 572 ultimately effects deployment or retraction of monopolarassembly 200 (FIGS. 2A-2D). Upon release of the actuator(s), the energybuilt up in second biasing member 579 is released, thereby urging secondend 579 b of second biasing member 579 to rotate back towards itsinitial position. During such rotation, second end 579 b of secondbiasing member 579 cams over the angled surfaces of one-way teeth 575 bsuch that second biasing member 579 is returned to its initial positionwithout effecting rotation of first pulley wheel 572.

The various embodiments disclosed herein may also be configured to workwith robotic surgical systems and what is commonly referred to as“Telesurgery.” Such systems employ various robotic elements to assistthe surgeon in the operating room and allow remote operation (or partialremote operation) of surgical instrumentation. Various robotic arms,gears, cams, pulleys, electric and mechanical motors, etc. may beemployed for this purpose and may be designed with a robotic surgicalsystem to assist the surgeon during the course of an operation ortreatment. Such robotic systems may include remotely steerable systems,automatically flexible surgical systems, remotely flexible surgicalsystems, remotely articulating surgical systems, wireless surgicalsystems, modular or selectively configurable remotely operated surgicalsystems, etc.

The robotic surgical systems may be employed with one or more consolesthat are next to the operating theater or located in a remote location.In this instance, one team of surgeons or nurses may prep the patientfor surgery and configure the robotic surgical system with one or moreof the instruments disclosed herein while another surgeon (or group ofsurgeons) remotely control the instruments via the robotic surgicalsystem. As can be appreciated, a highly skilled surgeon may performmultiple operations in multiple locations without leaving his/her remoteconsole which can be both economically advantageous and a benefit to thepatient or a series of patients.

The robotic arms of the surgical system are typically coupled to a pairof master handles by a controller. The handles can be moved by thesurgeon to produce a corresponding movement of the working ends of anytype of surgical instrument (e.g., end effectors, graspers, knifes,scissors, etc.) which may complement the use of one or more of theembodiments described herein. The movement of the master handles may bescaled so that the working ends have a corresponding movement that isdifferent, smaller or larger, than the movement performed by theoperating hands of the surgeon. The scale factor or gearing ratio may beadjustable so that the operator can control the resolution of theworking ends of the surgical instrument(s).

The master handles may include various sensors to provide feedback tothe surgeon relating to various tissue parameters or conditions, e.g.,tissue resistance due to manipulation, cutting or otherwise treating,pressure by the instrument onto the tissue, tissue temperature, tissueimpedance, etc. As can be appreciated, such sensors provide the surgeonwith enhanced tactile feedback simulating actual operating conditions.The master handles may also include a variety of different actuators fordelicate tissue manipulation or treatment further enhancing thesurgeon's ability to mimic actual operating conditions.

From the foregoing and with reference to the various drawing figures,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. While several embodiments of the disclosure have been shownin the drawings, it is not intended that the disclosure be limitedthereto, as it is intended that the disclosure be as broad in scope asthe art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

1-20. (canceled)
 21. An actuation mechanism for actuating a feature of asurgical instrument the actuation mechanism comprising: an actuatorconfigured to provide a rotational input; a drive assembly configured toreceive the rotational input from the actuator and, based thereon,provide a rotational output; an arm configured to receive the rotationaloutput from the drive assembly and to rotate in response thereto; and aslider coupled to the arm such that, in response to rotation of the arm,the slider is translated to thereby actuate a feature of a surgicalinstrument, wherein a ratio of a degree of rotation of the actuatorrelative to a degree of rotation of the arm is less than or equal to1:3.
 22. The actuation mechanism according to claim 21, wherein thedrive assembly includes: a first pulley wheel configured to receive therotational input; a second pulley wheel configured to provide therotational output; and a pulley belt operably coupled between the firstand second pulley wheels and configured to transfer rotation of thefirst pulley wheel to the second pulley wheel.
 23. The actuationmechanism according to claim 21, wherein the drive assembly includes: afirst gear configured to receive the rotational input; a second gearconfigured to provide the rotational output; and an intermediate geardisposed in meshed engagement with each of the first and second gearsand configured to transfer rotation of the first gear to the secondgear.
 24. The actuation mechanism according to claim 21, furthercomprising a clutch assembly coupled between the actuator and the driveassembly such that the rotational input in a first rotational directionis provided to the drive assembly and such that rotational of theactuator in a second, opposite rotational direction is not provided tothe drive assembly.
 25. The actuation mechanism according to claim 21,further comprising: a hand disposed at a free end portion of the arm;and a track defining a slot, wherein the hand is slidably engaged withinthe slot and the slider is coupled to the track such that rotation ofthe arm moves the hand along the slot to translate the track and therebyurge the slider to translate.
 26. The actuation mechanism according toclaim 21, further comprising: a linkage bar having a first end portionand a second end portion, the first end portion pivotably coupled to afree end portion of the arm, wherein the slider is pivotably coupled tothe second end portion of the linkage such that rotation of the armmoves the linkage to thereby urge the slider to translate.
 27. Asurgical instrument, comprising: a housing; an assembly extendingdistally from the housing; and an actuation mechanism at least partiallydisposed within the housing and operably coupled with the assembly, theactuation mechanism including: an actuator configured to provide arotational input; a drive assembly configured to receive the rotationalinput from the actuator and, based thereon, provide a rotational output;an arm configured to receive the rotational output from the driveassembly and to rotate in response thereto; and a slider coupled to thearm such that, in response to rotation of the arm, the slider istranslated to thereby actuate the assembly, wherein a ratio of a degreeof rotation of the actuator relative to a degree of rotation of the armis less than or equal to 1:3.
 28. The surgical instrument according toclaim 27, wherein the drive assembly includes: a first pulley wheelconfigured to receive the rotational input; a second pulley wheelconfigured to provide the rotational output; and a pulley belt operablycoupled between the first and second pulley wheels and configured totransfer rotation of the first pulley wheel to the second pulley wheel.29. The surgical instrument according to claim 27, wherein the driveassembly includes: a first gear configured to receive the rotationalinput; a second gear configured to provide the rotational output; and anintermediate gear disposed in meshed engagement with each of the firstand second gears and configured to transfer rotation of the first gearto the second gear.
 30. The surgical instrument according to claim 27,wherein the actuation mechanism further includes a clutch assemblycoupled between the actuator and the drive assembly such that therotational input in a first rotational direction is provided to thedrive assembly and such that rotational of the actuator in a second,opposite rotational direction is not provided to the drive assembly. 31.The surgical instrument according to claim 27, wherein the actuationmechanism further includes: a hand disposed at a free end portion of thearm; and a track defining a slot, wherein the hand is slidably engagedwithin the slot and the slider is coupled to the track such thatrotation of the arm moves the hand along the slot to translate the trackand thereby urge the slider to translate.
 32. The surgical instrumentaccording to claim 27, wherein the actuation mechanism further includes:a linkage bar having a first end portion and a second end portion, thefirst end portion pivotably coupled to a free end portion of the arm,wherein the slider is pivotably coupled to the second end portion of thelinkage such that rotation of the arm moves the linkage to thereby urgethe slider to translate.